The present invention relates to a structure and manufacturing method for a micro-pump and micro-valve in medical fields and analytic fields wherein essentially required are liquid feed of a slight amount of a liquid with accuracy and miniaturization of the apparatus itself.
There is one described, for example, in JP-A-5-164052 as a micro-pump being applied in the analytic field and the like. This invention is structured, within a casing 26 as shown in FIG. 2, by a fixed stacked-type piezoelectric actuator bonded at its end face with a liquid suction and discharge member 21, and two stacked-type piezoelectric actuators 22 bonded at their end faces with valves 23, so that a structure is provided that liquid feed is realized through a passage pipe port 24 and a pump chamber 25 by driving the three actuators.
Also, in the case of a micro-pump described in JP-A-5-1669, it is characterized as shown in FIG. 3 in that a metal or polysilicon thin film 32 is formed on a sacrificial layer of an oxide film over a silicon substrate 31, further a metal or polysilicon check valve is structured by removing the sacrificial layer through etching, and a pump is structured by a piezoelectric element 34 provided on a glass substrate 33.
Meanwhile, in the case of a device described in JP-A-5-263763, a structure is made as shown in FIG. 4 by attaching two pump-driving bimorph type piezoelectric elements 42 on and under a pump chamber 41, and mounting flow control valves 45 formed by a valve body 43 and a bimorph type piezoelectric element 44 to a suction port and a discharge port, so that the pump-driving piezoelectric elements 42 and the fluid control valve piezoelectric elements 44 can be drive-controlled by a same controller 46.
In a case where an active valve is manufactured by using a stacked-type piezoelectric element as shown in FIG. 2 as its actuator, there has been a problem that the reduction in thickness was impossible due to the thickness of the stacked type piezoelectric element itself.
Also, in the micro-pump having the two check valves as shown in FIG. 3, there has been a problem that liquid feed is possible in only one direction due to its liquid feed realized by using the passive check valves.
Further, where using as shown in FIG. 4 the valve by directly closing the passage with the piezoelectric element bimorph type actuators, there has possessed a problem that the actuators had to be protected because fluid contacts with the actuator.
Therefore it is an object in the present invention to realize a micro-pump which is realized high in tightness, capable of being made thin and high in pressure resistance and discharge efficiency, by using a unimorph actuator to obtain sufficient displacement in a diaphragm of a substrate portion and using such a structure as clamping a packing such as silicone rubber between the substrate portion and the ceiling plate portion.
Furthermore, it is another object in the present invention to realize a micro-pump which is realized high in tightness, capable of being made thin and feeding liquid bi-directional, and high in pressure resistance and discharge efficiency, by using a unimorph actuator to obtain sufficient displacement in a diaphragm of a substrate portion and using an integral structure with a substrate portion or ceiling plate portion and a packing.